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The CAROL AI Bike – The Future Of Home Fitness Or Just A Fad? [A Review]

carol ai bike review

If you’re tired of hearing about streaming bikes and how wonderful they are, the CAROL AI Bike might be more your speed- especially if you like the idea of exercising for less than 10 minutes at a time.

Powered by an artificial intelligence that calculates your personalized resistance level, the CAROL Bike is designed to help you meet your fitness goals in less time than any other more traditional exercise routine.

It does this by putting you through 2, maximum effort sprints per workout.

Did I mention that each sprint is only 20 seconds and the total workout time is less than 9 minutes?

Yeah, these workouts are quick- so the biggest drawback about the CAROL is that you won’t be able to say you don’t have enough time in the day to exercise.

Long-story-short: the CAROL Bike seems to be pretty legit- with science on its side, it looks like these short, intense workouts are quite effective.

But with a price tag north of $2k, this bike certainly isn’t for everyone.

My goal for this review is to help you decide whether or not this bike is the right choice for your home gym.

So, if you’re interested in the longer story, keep reading.



CAROL isn’t only a catchy name for this bike, it also stands for CARdiovascular Optimization Logic (CAROL is a lot catchier if you ask me).

The idea being that the artificial intelligence program built-into this bike optimizes the resistance for you automatically in order for you to get the most out of every single workout.

And in a lot less time.

The bike also tracks your performance with each workout and continues to progress your resistance levels as needed to ensure you continue to make progress over time.

The CAROL Bike is based out of the UK, but it’s still readily available for shipment to the US.

This bike goes for a full retail price of about $2400 for just the bike and there are a few different bundles available depending on what accessories you want.


  • Heavy flywheel
  • Heavy-duty frame
  • Fully adjustable seat
  • Dual-compatible pedals
  • Short, intense workouts designed to reach goals in less time
  • Console controls resistance for you
  • Resistance gets more difficult automatically as you improve
  • 6 workout modes
  • Tracks all key workout metrics
  • Peloton Digital compatible
  • Bluetooth headphones/chest strap compatible


  • No multi-grip handlebars
  • Have to pay extra for tablet/water bottle holders
  • Short warranty


It may sound too good to be true that you can workout for 9 minutes a day, 3x a week and get in the best shape of your life, but the science behind this claim is real.

And it’s been around for quite some time.

You may’ve heard of high intensity interval training (HIIT), well this is basically just a version of the tried and true system that’s been getting folks into great shape for a long time.

Although the folks at CAROL refer to it as reduced exertion high intensity training, or REHIT for short.

REHIT is just like HIIT, except that the intervals aren’t just “high intensity”, they’re all out maximum intensity. And since these short intervals are at all out intensity, you don’t have to do as many of them to get the same results.

The idea is that these short, intense bouts of exercise deplete your muscles’ glycogen stores, which in turn leads to multiple benefits for your body.

Among these being fat loss, improved cardiovascular health, improved metabolic flexibility, lower triglyceride levels, and improved blood sugar readings.

Exercising to the point where your glycogen levels are depleted, forces your body to find a way to replete them, which often includes burning stored fat.

Research on these claimed benefits have shown that what the CAROL says it can do turns out to be true- when compared to a more traditional, steady-pace workout routine, the CAROL workouts showed significantly improved benefits in several categories.

Another added benefit is that exercising like this, even though it’s very short lived (only 2 20 sec intervals), tends to increase you metabolism for the rest of the day.

This leads to an increased calorie burn for hours after your workout is finished…which is awesome for the folks trying to lose weight.

Overall, the scientific theory behind why the CAROL is so effective isn’t new- it’s just HIIT with an emphasis on maximum exertion during intervals.

And HIIT has been proven time and time again to be very effective.

So, when it comes to scientific theory, it makes sense that the CAROL Bike would be effective (assuming the intervals push you hard enough).

Bike Specs

Ok, so the theory behind this bike is sound, but what about the bike itself?

After all, if I’m thinking about dropping 2 grand on an exercise bike, I want that bike to be high-end to the nth degree.

The CAROL Bike itself is pretty compact and heavy-duty. It comes with a black steel frame that weighs 130 lb fully assembled and it comes with a max weight capacity of 286.6 lb (130 kg, keep in mind this is a UK brand).

Both of these stats are pretty good for a spin bike and they are in line with the numbers the other elite indoor cycles are packing.

This bike comes with a rear-mounted flywheel that weighs 30.8 lb (14 kg), which is more than heavy enough to ensure a smooth ride.

Especially when paired with a smooth acting, magnetic resistance system.

The CAROL comes with a fully adjustable seat, which allows you to adjust both the height and horizontal (fore/aft) position for a custom fit.

The only thing really missing from this bike is a set of multi-grip handlebars.

If you’ll notice, the handles on this bike are a bit odd- certainly not something you’d expect to see on an indoor cycle. They only offer the single hand position, but they do have built-in grip heart rate monitors.

I’m guessing the handlebars were designed like this because the workouts you’ll be doing on this bike aren’t like the traditional spinning workouts where you’re standing sometimes and changing hand positions.

But I still think it would be nice to see a more traditional set of handlebars.

Anyway, the handles are height adjustable, so there’s that.

The pedals are dual-compatible, meaning you can use cleats (SPD) or sneakers depending on your preference, which is always a nice touch.

The flywheel is also designed with a safety clutch, which keeps the pedals from spinning on their own if you take your feet off the pedals- not a huge deal if you ask me, but still a nice safety feature.

When it comes to the console, this bike comes with a 10.1″ touchscreen display that’s Android powered.

This is about half the size of the larger, touchscreen consoles we’re used to from brands like Peloton and NordicTrack, but keep in mind the CAROL doesn’t provide instructor-led workouts.

That said, you can access the Peloton Digital App directly from this console if you want, which is pretty awesome.

So, the tablet on this bike is smaller than other brands, but it’s still large enough to see all your stats clearly during your workouts.

Overall, the CAROL is a well constructed bike with a heavy-duty frame and a heavy flywheel. It’s lacking multigrain handlebars, but it has everything else you’d expect from an elite cycle.


The biggest difference between the CAROL Bike and any other indoor cycle is the programming.

The AI based programming that CAROL uses controls the intensity of the workouts to ensure you’re working hard enough to reap all the advantages.

In order to do this, the bike needs to learn where you are with regards to your fitness level.

The first 3 rides you take will be very light duty with only 10 second sprints- these are like practice for the real workouts to come.

Your 4th – 6th workouts will give you the choice between 10, 15, or 20 second sprints. During these workouts, the console is figuring out how hard it needs to push you.

After your 6th ride, you’ll be able to choose your workout from the full menu.

With the CAROL Bike, you can choose between 6 different workout modes: intense, energizer, fat burn, constant power, endurance, and free ride.

The “intense” mode is their lead workout- this is the one that only lasts 8 min and 40 seconds and consists of a 2 min warm up, 2 20 sec intervals with a recovery between, and a cool down.

When done at least 3x/week, this is the workout that’s been shown to be so effective at improving cardiovascular health and overall fitness.

The “energizer” is a slightly less intense workout, utilizing only 10 sec intervals (still only lasts a little over 8 min total).

The “fat burn” workout can last either 15 min or 25 min, but both consist of 8 sec sprints and 12 sec recoveries during the intervals.

The “constant power” option lets you set your desired power outcome and then you see how long you can sustain it. The resistance will automatically change based on your cadence to ensure you maintain your watt output.

The “endurance” setting is designed to see how much output you’re capable of providing, as the watt output gradually increases until you reach your breaking point.

And then there’s the “free ride”, which functions as a manual mode- you can set the time and resistance and ride any way you like.

You can also download the Peloton Digital App onto the console and access the Peloton workouts using the “free ride” mode (you’d have to pay the Peloton monthly fee separately of course).

With the exception of the “free ride” mode, the CAROL is in charge of controlling the resistance for all of your workouts, so you don’t have to worry about increasing or decreasing the intensity during your workouts.

You get on, choose your workout mode, choose your music, and start pedaling.

Most users agree the interval sections, although short, are very intense. The only real complaints I’ve come across are that (believe it or not) the workouts are too short.

The folks who are used to instructor-led workouts that last 30-45 min might feel a little short changed doing a 9 min workout.

Of course those folks can always choose one of the other workout modes that last longer.

Something else that’s kinda cool is that the console talks to you during your workouts, trying to guide and motivate you during your intervals.

During your workouts, the console displays key metrics, like watt output, RPM, and heart rate, as well as historical data like “best peak power” and “last max heart rate”.

And like most smart bikes these days, CAROL can track your performance over time so you can see how much fitter you’re getting.

Something I want to make sure everyone knows is that the bike is controlling your resistance during these workouts. And as you get stronger, it gives you more resistance to work against.

This means the workouts never get easier, even though you’ll be getting stronger and more fit.

Overall, if you’re looking for instructor-led workouts, this isn’t the right bike for ya. But if you like the idea of quick, efficient workouts that will always keep you working, you’ll probably like the CAROL workouts.

Oh, almost forgot- this bike is compatible with bluetooth headphones and chest strap heart rate monitors.

Oh, oh, I also almost forgot- you have to pay a monthly subscription fee of $12 to access the AI this bike has to offer (although I think they give you 3 free months at time of purchase).


The CAROL AI Bike comes standard with the following warranty:

  • 1 year

Ok, so this is a really short warranty for a bike that costs $2400. For this price range, I’d like to see at least a 5 year frame warranty and 2-3 years on parts.

With the CAROL Bike, your warranty actually depends on which bundle you purchase.

The 1 year guarantee is what you get if you purchase the bike only. If you get the Standard Bike Bundle (which includes a chest strap and a tablet holder), the warranty is extended to 2 years.

The Premium Bike Bundle, which includes the chest strap, tablet holder, water bottle holder, and mat, comes with a 3 year warranty.

I’ve got a couple of complaints here.

First, I don’t think we should have to pay more for a tablet holder and a water bottle holder- these are normal features that should come standard.

And even at 3 years, that’s still a really short warranty for a bike that almost costs $3000.

Overall, I think the warranty department is one of the biggest drawbacks of this bike.

Final Thoughts

Alright folks, I think it’s about time for me to wrap this article up.

Overall, I think the CAROL Bike is an interesting concept. The bike itself looks very high-end and all the performance specs are legit.

And the idea of getting your daily workout completed in less than 9 min (without having to touch a resistance knob) sounds great too.

I also certainly don’t think this bike is a fad- the theory behind it is based on sound science and this bike is more than capable of pushing you to the limits of what you think you’re capable of.

But I do have a few complaints when it comes to the features.

As I just mentioned, I think the tablet holder and water bottle holders should come standard- I don’t like the idea of having to pay more to get them.

Especially when the bike already costs over $2k.

The warranty is another drawback- regardless of which bundle you choose, you’re still getting a pretty weak warranty with the CAROL.

That said, if you’re tired of all the high-energy, instructor led workouts out there, the short to the point workouts this bike offers might be exactly what you’re looking for.


Will's a licensed physical therapist (DPT) with over 15 years of experience treating patients from all backgrounds. He's been lifting weights and exercising in one form or another since middle school and has been working out in his own home gym for over a decade. When it comes to fitness equipment, there isn't much he hasn't tried. In his spare time, if he isn't writing or working out, he's likely playing basketball, watching movies, or hanging with his family.

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